Project Summary/Abstract Tsetse flies transmit the human and animal forms of African Trypanosomiasis, neglected diseases, which affect marginalized populations in sub-Saharan Africa. Tsetse flies have a low reproductive capacity and low population numbers relative to other disease vectors as they reproduce by obligate viviparity (intrauterine larval development/nutrition and live birth). Trypanosomiasis is controlled primarily by vector control methods based upon pesticide-baited targets and traps to reduce tsetse populations. These strategies are effective, but have downsides, including pesticide associated toxicity and high implementation cost. Thus, improvement of the current control methods by increasing efficacy and reducing toxicity/associated costs as well as development of new strategies is desirable. This project will produce knowledge required for the development of control methods that exploit tsetse's unique reproductive biology and low reproductive capacity for vector control. Male seminal fluid proteins regulate important physiological and behavioral changes observed in mated female insects, including reduced receptivity to remating, increased blood meal volume, initiation of ovulation and morphological modifications to the female reproductive tract. Manipulation of the formation of the seminal secretions in males or the post-mating responses in the female has the potential to disrupt tsetse reproduction. The aims of this project will define the physiological, molecular and metabolic responses occurring in the female in response to mating/seminal secretion transfer as well as identify seminal biochemical compounds and their associated metabolic pathways. This study has 2 aims: 1. Characterize molecular and morphological changes associated with the female post-mating response. 2. Identify metabolites/pathways associated with male seminal secretions and metabolic changes in the female associated with the post mating response.